In several settings it is desired to be able to remotely control your camera and although there are some options for remote control of the EOS-1 series, I am a bit puzzled why there is no long-range option available from Canon that does not require line-of-sight (i.e. IR). I have been experimenting with flash light modelling and although you can have wireless (infrared) control of your flashes from the body, the practical working range outdoor is very limited. Further, I have found that a very different effect can be achieved in complete darkness by having the camera on a tripod with long shutter opening times. Walking away with the flash and manually triggering it, including having multiple flashes and/or firing the same flash "painting" into different directions gives additional creative tools. However, in the darkness of a mine it is very difficult (and dangerous) to trigger the camera, walk away some 10-15 meters and then fire the flash. Some 30 seconds of shutter opening and a very weak light source has been my previous mode of operandi. Although Canon's long-time exposure noise reduction is excellent, shorter exposure times is desired to get the shadow noise down to a minimum.

I therefore decided to build my own radio remote. As an electronic engineer it should not be that hard to make a one-way radio solution with some 10-20 meters range. But as usual, rather than building one yourself from scratch, I found a highly competitive off-the-shelf option at a general hardware store: A SEK 89 (Approx US$ 11) wireless door chime with 30 meters (100ft) stated range plus a SEK 7.5 (US $1) opto coupler.

If you have some experience with building simple electronics, it is a swift thing to put together. For my Canon 1DmkII, I used the RS-80N3 remote switch to trigger the camera and soldered in an opto-coupler into the door chime unit. The conveniently sized pushbutton unit was my portable trigger.

My first experiments with this remotes were carried out deep down into an abandoned mine. Some pictures can be found at: https://pbase.com/jakobe/deep_shadows

There are several ways to skin a cat, but my assembly looks like this:
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